452 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
KEY TO THE SPECIES. 
Some of the spines hooked. 
Central spines 1, hooked, some of the laterals also hooked, 
slender, terete, about 10 cm. long; plants small, 
about 10 cm. high..................-.---2-------- 1. E. uncinatus 
wrightit. 
Centrals 4, stout, flattened or quadrangular, 5 to 7.5 cm. 
long (rarely 10 cm.); plants often large, up to 90 
cm, high and 30 cm. in diameter. 
Plants small, 10 cm. high or less, 8 cm. or less in di- 
ameter........-..---------2 2222 eee eee eee ... 2. E. glaucus. 
Plants large, 50 cm. high or over, more than 30 cm. 
in diameter........-...--------+-------------- 3. EL wislizent. 
None of the spines hooked. 
Centrals 2 to 4, not stout; plants small, 10 cm. high or 
less. 
Spines flat, flexible, chartaceous; ridges broken into 
tubercles. .......22.--..-2-2222 22222000 ee eee 4. E. papyracanthus. 
Spines terete, stiff though small; ridges continuous.. 5. FE. intertextus. 
Centrals 1 or none, very stout and horny; plants larger, 
10 to 25 em. in diameter. 
Ribs few, 8 to 10, rounded; spines mostly terete; 
plants about 10 cm. in diameter, spheroidal... 6. E. horizonthalonius. 
Ribs more numerous, 13 to 21, more acute; spines 
compressed; plants 20 to 30 cm. in diameter, 
depressed .......----222.. 202-2 e eee ee eee ee eee 7. E. texensis. 
1. Echinocactus uncinatus wrightii Engelm. Proc. Amer. Acad. 8: 277. 1856. 
Type Locauity: ‘‘Near El Paso and on the river below.”’ 
Rance: Southern New Mexico, trans-Pecos Texas, and adjacent Mexico. 
New Mexico: Pena Blanca; Bishops Cap. Lower and Upper Sonoran zones. 
A rare species, known in New Mexico only from the dry foothills in the southern 
part of the State. It is subcylindric to almost hemispheric, about 10 cm. high and 
nearly as great in diameter, not including the long, slender, hooked, yellow spines, 
which are sometimes twice as long as the body of the plant. The ribs are rather 
prominent, the radials about 8, slender, light-colored; the flowers are small for the 
genus, about 25 mm. long, of a dull brownish purple and glabrous. 
2. Echinocactus glaucus Schum. Gesamtb. Kakt. 438. 1903. 
Type Locauity: Dry Creek, Mesa Grande, Colorado. 
Rance: Colorado and Utah to Arizona and northwestern New Mexico. 
New Mexico: Carrizo Mountains; Shiprock. Dry hills, in the Upper Sonoran 
Zone. 
8. Echinocatus wislizeni Engelm. in Wisliz. Mem. North. Mex. 96. 1848. 
VIZNAGA. 
Type Loca.ity: Near Dona Ana, New Mexico. Type collected by Wislizenus 
in 1846. 
Rance: Utah and Arizona to western Texas and neighboring Mexico. 
New Mexico: Pena Blanca; mesa west of Organ Mountains; Filmore Canyon; 
Little Florida Mountains. Lower Sonoran Zone. 
The largest cylindric-stemmed cactus found in our range. It is sometimes 70 to 
90 cm. high and mostly about 40 to 50 cm. in diameter. The spines are numerous; 
the lowest radials are slender and whitish, the others stouter and rigid, and the 4 
centrals stout, reddish, banded, the lowest ones sometimes 5 or 6 cm. long, flattened 
and bony, strongly hooked downward. 
